1. Field of the Invention
This invention relates to a system whereby a combustion engine driven vehicle including an auxiliary drive may draw fuel for the combustion engine from a primary fuel tank when the vehicle is being operated over the road, but including an auxiliary fuel tank from which fuel is drawn for the engine only when the auxiliary drive is being operated and the truck is not being operated over the road.
2. Description of Related Art
Various different forms of fuel flow controlling systems heretofore have been provided such as those disclosed in U.S. Pat. Nos. 2,304,276, 3,288,238, 3,512,600 and 4,287,908.
U.S. Pat. No. 3,288,238 discloses a fuel diversion system incorporating some of the features of the instant invention including primary and secondary auxiliary fuel tanks and means for normally supplying fuel to an associated engine from the primary fuel tank and operative to supply fuel from the secondary or auxiliary fuel tank to the engine only when the vehicle is stationary. However, this prior patent discloses a single diversion valve which may in fact develop internal leaks and allow the crossing of fuel from one tank to another. Further, the prior patent device also includes control means for the fuel diversion valve which is not operative only in response to actuation of the auxiliary drive and may, in fact, be actuated when the vehicle is stationary and the auxiliary drive is not in operation.